SFD PCD die blanks are polycrystalline diamond (PCD) products produced by an advanced high temperature and ultra-high pressure process in the presence of a solvent/catalyst metal. A high degree of diamond-to-diamond bonding enables them to combine the hardness, abrasion resistance and high thermal conductivity of natural diamond with a toughness approaching that of tungsten carbide. They are the better choice for high precision and long life wire drawing dies.

There are 1μ、3μ、5μ、10μ、25μ and 50μ grain sizes available. Two types of blanks can be supplied: one is self-supported and comes with a round or hexagonal shape, while the other is supported by tungsten carbide and can thus withstand greater drawing forces. CD die blanks can be used for stainless steel, copper, aluminium, nickel and their alloys etc.

CD die blanks contains catalyst metal and are thermally stable to 650℃, and they are to be mounted at temperatures not exceeding 650℃. CD DIE blanks are electrically conductive and can be drilled and shaped by EDM, laser and ultrasonic etc.

PCD Grain Size Applications:

PCD Microstructure from Scanning Electron Microscope (SEM):

Excellent Wire Surface & Toughness

3 micron

5 micron

10 micron

25 micron

50 micron

Longer Life

3 μm and 5 μm Grain Sizes

Nonferrous and ferrous wire in finer sizes

Critical surface finish applications

10 μm and 25 μm Grain Sizes

Nonferrous and ferrous intermediate and fine wires

Superior surface quality applications

50 μm Grain Sizes

Drawing of nonferrous materials like copper, aluminium and others

Longer die life

EQ Grade Diamond Die Blanks for Wire Drawing

EQ series is completely developed CD series. Compared with CD series, its grain size looks more concentrative, even and compact from micro structure, which increased its wear resistance. Meanwhile carbide supported EQ use high quality sintering powder and new production technology. Carbide ring can give PCD better support.

TSL series is leached PCD. It is thermally stable up to 950℃ in an inert or reducing atmosphere, and can be mounted at high temperature with high stength metal setting powders. TSL is not electrically conductive and can be drilled and shaped by ultrasonic and laser etc, EDM not recommended.

In order to check the quality of PCD die blanks, SFD established an advanced die making laboratory, and equipped it with world-class testing and inspection equipment both for product development and quality control. During the process of testing and inspecting wire dies, SFD developed the comprehensive know-how needed to make these as finished and semi-finished dies. This includes how to mount PCD DIE blanks in the case and how to make the central hole quickly and correctly. SFD also polished dies to check the PCD internal structure.

With this development, SFD has established a workshop to supply our customers with a broad array of services and technical support in the die making process. This includes providing customers with semi-finished dies at various stages of completion, up to finished dies. This also means SFD can lend their expertise in troubleshooting die making problems for their customers.

From die blanks only, or for mounted, drilled or polished semi-finished to finished dies, SFD is you most convenient source in the wire die industry.

Each batch of SFD PCD die blanks has parts selected at random to make semi-finished dies and finished dies in our workshop, which are then closely inspected. Among other tests, these PCD dies are confirmed by Conoptica, which clearly shows the internal profile of the finished die.

In SFD, you will enjoy your buying convenience: Complete PCD die blanks and all kinds of semi-finished PCD dies with case, central hole or surface polish.

Each batch of our PCD die blanks has to be chosen in random to make semi-finished dies and finished dies at our die making lab. These PCD dies will be checked by Conoptica, which show us a clear profile.

PCD DIE New Application: PCD Shaving Die
In recent years, with the increased use of aluminum and aluminum alloys, the need for aluminum-magnesium, aluminum-silicon and other aluminum alloy welding materials has grown year by year. The applications of aluminum wire in fabrication includes high-speed trains, subway trains and train carriages, speedboat carriers, aerospace components, household appliances and similar items. However, because of the nature of wire drawing and material characteristics specific to making aluminum wire, the wire surface will accumulate impurities and oxides. Removing these impurities and oxides from the wire surface is the key issue in making high-quality aluminum wire.

The standard method of improving the surface condition of aluminum wire is to use a shaving die. A shaving die is a circular cutting tool with a sharpened interior edge. When aluminum wire is pulled through a shaving die, this inner edge acts as a sharp blade and shaves off the impurities and oxides from the wire surface.

The standard process for shaving aluminum wire is to use Tungsten Carbide (“TC”) shaving dies. But TC shaving dies have a relatively short lifetime. Also the surface of wire shaved using TC shaving dies is still not a high-precision surface, and the surface finish can be inconsistent.

To solve these problems, shaving dies made using polycrystalline diamond (“PCD”) have been developed. These have proven to provide a superior surface finish and improved consistency in aluminum wire

1. Why do tungsten carbide shaving dies produce lower quality aluminum welding wire?
The hardness of TC is very high, and the sharpness of the inner circular edge depends on the hardness of TC. Another key factor in the sharpness of the shaving die and its shaving action is the rake angle of the inner edge. A larger rake angle also improves the shaving action of the die. But using higher hardness TC and higher rake angles both decrease the strength of the shaving die’s inner circular edge. If there are excessive vibrations, shock or other inconsistencies in the shaving process, the shaving die inner edge blade can be easily chipped, and the shaving die can no longer be used.

TC shaving dies also generate a large amount of heat which will cause the aluminium wire to overheat and discolor. This means steps are required to cool the wire during shaving, and clean the wire in a later process step, which will increase the production cost.

In addition, TC will often vibrate slightly when shaving. Even if these small vibrations do not cause chipping, they will still leave traces in the wire surface, and if large enough will cause visibly concave gouges in the wire OD which cannot be removed in subsequent steps. This is one of the most serious quality problems in the aluminum wire surface. (Refer to illustration: Tungsten Carbide Shaving Die Model)

Advantages: production process is simple, price is competitive.
Disadvantages: short lifetime, poor consistency of aluminum wire, surface defects, high temperature.

2. How do PCD shaving dies produce high quality aluminum welding wire?
Polycrystalline diamond (PCD) is comprised of diamond powders and a catalyst metal, and are sintered into an ultra-hard composite material using an advanced high temperature and ultra-high pressure process. The PCD material has the hardness and wear resistance of diamond, and as a composite material has every good toughness as well, which makes for better for wire surfaces and consistency. Diamond also has a low coefficient of friction and very high thermal conductivity, so the heat generated during shaving is lower and the heat is removed from the working surface more quickly, eliminating the chance of overheating the wire.

Because of the high hardness of PCD, the inner edge shaving blade stays very sharp for a long time, so the rake angle can be much less aggressive than needed for TC shaving dies. This also increases the effective area of shaving die blade. In order to eliminate vibration during shaving, a cylindrical bearing area is incorporated into the PCD shaving die adjacent to the cutting edge, which stabilizes the wire. (Refer to illustration: PCD Shaving Die model)

PCD Shaving Die Model

Advantages: competitive price, long lifetime, very good consistency, very high wear resistance and impact resistance, fast heat dissipation.

3. PCD Shaving Die Application
Because there is a bearing area, the aluminum wire has support from PCD shaving die ID, which is the same diameter as the die cutting edge. Because vibration is eliminated, the aluminum wire surface shaved by a PCD die is much better than that shaved by a TC die. In the following pictures, we see that the aluminum welding wire shaved by a PCD shaving die is shiny, has a light and even color, and the wire surface quality is much better than that drawn by a TC die.

Generally speaking, the lifetime of PCD shaving dies is from 10X up to 30X longer than that of TC dies, while providing aluminum wire with much better surface finish.

TC Shaving Die

PCD Shaving Die

Yield

2 Rolls / die

20-40-60 Rolls / die

In summary, because of the premium performance of PCD in the shaving process, PCD shaving dies are replacing TC dies in ever-increasing numbers. PCD shaving dies are proving to be by far the best choice for this application.